Why NASA’s first planetary defense mission sent a spacecraft crashing into an asteroid

Last night NASA completed a first-of-its-kind mission to steer a spacecraft into an asteroid. The asteroid was not hurtling toward Earth, threatening to wipe out civilization, and the goal was not to blast it to smithereens, “Armageddon” style, but rather to give it enough of a bump to slightly change course. The Double Asteroid Redirection Test, or DART, took aim at a small asteroid called Dimorphos, which is about 11 school buses wide. It’s orbiting a bigger asteroid called Didymos, about 7 million miles from Earth. Marketplace’s Meghan McCarty Carino spoke with Nancy Chabot, DART mission coordination lead at the Johns Hopkins Applied Physics Laboratory, about the mission.